LAS VEGAS — Six days after costing Oregon a share of the Pac-12 regular season title, the Ducks paid Utah back — denying the Utes an opportunity to face UCLA for the conference tournament championship.

Oregon is going instead after a 64-45 victory over Utah in the semifinals Friday night at the MGM Grand Garden Arena.

The Ducks (25-8) flew past the Utes (15-17) in impressive fashion, holding them to a season-low 15 points in the decisive first half. In the process, they held Utah’s top three scorers (Jordan Loveridge, Jarred DuBois and Jason Washburn) to a combined total of just three points on 1-of-10 shooting over the first 20 minutes.

“I don’t believe we were down,” said Utah coach Larry Krystkowiak. “They’re a real good defensive team and they took us out of a lot of the stuff that we wanted to do.”

Utah's Renan Lenz, right, passes the ball off against Oregon's Ben Carter in the first half of a semifinal Pac-12 tournament NCAA college basketball game, Friday, March 15, 2013, in Las Vegas. (Julie Jacobson, Associated Press)

Oregon led 29-15 at halftime. The Ducks trailed only once, at 3-0, before pulling away thanks to several statistical advantages. Besides outrebounding the Utes 18-10 in the first half, they held edges in points off the bench (13-4), points in the paint (12-4), points off of turnovers (10-2), second-chance scoring (4-0) and fast break points (5-2).

It all added up to a night of struggles for the 10th-seeded Utes, who entered the contest with a season-best four-game winning streak. The run included tournament upsets over USC (69-66) and California (79-69 in overtime).

Oregon, though, never allowed a scenario to materialize. The Ducks pulled away from a 6-6 tie with a 15-4 outburst to put the game out of reach early. They took their biggest lead of the half by closing things out with six straight points — holding the Utes scoreless for the final 4:46 in the process.

“I thought we played really hard the first half defensively. We didn’t want to give up any easy baskets,” said Oregon coach Dana Altman. “They had a couple of good looks that they missed. In fairness to them, that’s their third game and they had been shooting it so well.”

Things grew even more lopsided in the second half. In less than four minutes, Oregon extended its lead to 41-22. It provided an ample cushion for the Ducks to prevail, even though the Utes managed to make things interesting by closing the gap to eight midway through the second half.

Despite the outcome, Utah finished the year with its most wins since going 24-10 in 2008-09. This season’s 15 victories marked a nine-game improvement from last season, giving the Utes significant evidence of progress — especially the two tournament wins.

“It’s kind of hard to think about the week overall. I’m still stinging from this one,” Krystkowiak said. “But I’m very proud of our guys and their ability to continue to get better as the year went on.”

A win over Oregon would have added something else to the mix. The Utes were hoping to make the Ducks just the second Pac-12 team (along with Arizona State) they had defeated twice since joining the conference in 2011-12.

Utah surprised Oregon 72-62 last Saturday in the Huntsman Center — putting the Ducks on a list of conference foes the Utes had earned victories against. The group includes ASU, California, Colorado, Oregon State, Stanford, Washington and Washington State. Arizona and UCLA are the only teams Utah has yet to top in Pac-12 play.

The Wildcats and Bruins played in Friday’s other tournament semifinal. UCLA wound up winning 66-64, coming back from 11-points down over the final 10:24.

Utah’s margin of loss to Oregon is the largest in this year’s Pac-12 Tournament. The first nine games played were decided by a combined margin of just 42 points and included three overtime contests.

Oregon's Waverly Austin (20) dunks the ball against Utah in the first half during a semifinal Pac-12 tournament NCAA college basketball game, Friday, March 15, 2013, in Las Vegas. (Julie Jacobson, Associated Press)

The Utes failed to keep pace with the Ducks for a variety of reasons. Most notably, however, were 17 turnovers and 29.4 percent shooting from the field. Loveridge made just 1-of-10 shots, while DuBois missed the mark in all eight of his attempts. He was held scoreless after tallying 43 points over the first two games of the tournament.

“The team played its heart out tonight despite the outcome,” Washburn said. “I have to give credit to Oregon. They came to play tonight and completely took us out of our game from the beginning.”

EXTRA STUFF: Oregon was led by Damyean Dotson and E.J. Singler, who finished with 14 points apiece. Washburn closed out his Utah career with 12 points and nine rebounds. Taylor scored a team-high 13 points for the Utes but had no assists.